An Effective Solar Home in a Shady Area

Folks who live in cloudy climes can pick up some pointers from this successful sun-power pioneer, including how it works, doubled efficiency.

By the MOTHER EARTH NEWS Editors

| January/February 1982

Passive solar energy assists in heating the Matthews' home.

MOTHER EARTH NEWS STAFF

Back in 1967, when most of the world was still scoffing at
the notion that the sun could be a viable source of home
heat, a retired carpenter and construction millwright named
Henry Matthew built a six-room solar house on Oregon's cool
and very foggy coast. Over the course of the last 15
years, Henry's self-designed system — which consists of
725 square feet of water-type collectors and an
8,000-gallon storage tank — has furnished 75 percent of his
Coos Bay home's heat in bad years and as much as 90 percent to
95 percent most of the time!In fact, the monthly utility bill for his otherwise
all-electric, 1,444-square-foot dwelling rises from
approximately $18 in the summer to all of $22 in the
winter. Henry's solar success story so impressed the
University of Oregon that its scientists have spent the
past few years monitoring the system with a battery of
instruments.

A Solar Engineer Ahead of His Time

As you might suspect, Henry — a modest, soft-spoken
do-it-yourselfer — has had a long-time interest in
solar energy.

"When I was a boy," he recalls, "my father would tell me,
'Someday people are going to store up heat in the ground
... solar heat.' Then, when I was 40 or 45 years
old, after my father — who was a lawyer — retired in San
Diego, he wrote to me, 'If we could buy some of this
inexpensive desert land down here and put in a solar pump
to irrigate it with, we could make some money.'

"Dad's idea sounded good, so we located a book called
Direct Use of the Sun's Energy by Farrington Daniels. After he read that book, though, Dad decided
that the project would require too much work, and he backed
out. But, I was still sure it was feasible. Then I learned
that Harry Thomason had designed a successful solar house, and I knew right there that I could build
one, too — and maybe even improve upon his design.

"The people who've found solar energy unsatisfactory," he
contends, "usually don't pay enough attention to heat storage. Now we have rainy periods here, with no direct
sunshine at all, that last three weeks at a time. So we
have to be able to pack away the heat when it is
available. I also believe that most collectors are far too
small. Many that I've seen are about a third as large as
they should be. Of course, you can't blame people for
wanting to economize when they're buying expensive
commercial collectors at $20 to $30 a square foot ... but
when I built mine, the materials cost only about $1.00 to
$1.50 per square foot, so I made sure the panels were big
enough to satisfy my needs."

How Solar Powered Electricity Works

The Mathew's home's rooftop collector consists of a
south-facing, 5-foot-high, 80-foot-long array, installed
7 degrees from vertical. The frame is made of wood backed with
plywood and a 1-1/2-inch thickness of fiber-glass (for
fireproofing). The heart of the unit is a corrugated sheet
of aluminum coated with flat-black paint. A horizontal,
galvanized iron, parallel-fed 1/2-inch pipe runs along each
corrugation, and these are tied snugly to the aluminum
sheet with wire. Three slightly overlapping glass panels
(they're 1/16-by-20-by-30 inches), placed 1-1/2 inches away from
the aluminum, are used to make up each individual panel.
Near-vertical headers are positioned at the ends of the
collector — one to bring water in and the other to let
it out — and arranged so that no liquid can leave until
the collector is entirely full.

Another collector of the same general design (it has 325
square feet of surface area) sits on the ground in back of
the house, and there's a small unit on the east side that
flows into Matthew's electric water heater.

"A pump forces
water to the little collector," Mathew explains. "From
there it runs to the east leg of the backyard unit, flows
through it, then goes to an overhead pipe, where it
connects with the collector on the roof of the house. When
the sun's shining and the collectors are stagnated, the
water temperature can rise to as high as 175 degrees Fahrenheit."

Efficient Alternative Energy

Normally, according to the University of Oregon's studies,
the water temperature would be raised only 5 degrees if it
were to flow straight from one end of the rooftop collector
system to the other (of course, over a series of passes,
the temperature gain would be much higher). But, this
ingenious gentleman has doubled that per-pass figure by
simply gluing a single layer of aluminum foil to the roof
with black plastic cement — and anyone who's ever gotten
a sunburn while ocean fishing on an overcast day knows how
efficient a reflecting surface can be.

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"I used plastic cement, because it sets up quicker than
does the asphalt type. Then I rolled out the foil and
smoothed it down with a household mop. I imagine that in
regions with acid rain problems, the aluminum foil might
have to be replaced every 10 years or so, but mine's been
up a lot longer than that."

After the water is warmed by the collectors, it flows into
a 7-by-10-foot, 8,000-gallon tank, which Mathew welded together
him-self right on the premises. This container is buried
beneath the house and is surrounded by a 6- to 18-inch
insulated airspace that accommodates a cold-air intake and
a hot-air outlet.

"The tank," Matthew says proudly, "cost me $175 for all-new
steel. Since I've been careful to keep as much air out
of it as possible, it's developed only a few specks of
rust. It should last for another 60 years!

"I thought that the water held in the tank would get very
hot in the summertime, but it doesn't. In fact, it stays at
about 100 degrees. Then along in September and
October — just when the heat begins to be
needed — the temperature reaches its peak. Following
that, we usually have rain for weeks, and the water will
start to cool down. However, the tank's large storage
capacity still allows it to keep the house warm through
that period until — by the middle of December — we
start to get some sunshine again."

Whenever the thermostat shows unfavorable solar collection
conditions, the pump automatically stops and all the water
returns to the tank. Then, when the rooms need heat, hot
air from the space around the tank flows — by
convection — out of a grill high in the living room
while cold air returns to the tank through an intake
positioned below the fireplace.

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"The system provides a nice, even, quiet heat," Mathew
points out. "During the coldest months it keeps the living
room at 75 degrees Fahrenheit, while even the bedrooms and baths, which
have no heat vents, often reach 65 degrees."

There's also a large garage/workshop on the west end of the
house, but it's passively heated by an
attached greenhouse. The home displays a passive solar
component, too: a 7-foot overhang along the south
side of the dwelling, which lets the sun stream across the
front living area in the winter but shades the same rooms
in the summer.

This innovative house, with Mathew doing all the work
himself, cost about $10,000 to build. Of that, the
materials for the roof collector ran to $1,000 and those
for the backyard unit totaled about $325. But as Matthew
points out, material prices have more than doubled since
1967, so you can figure that it would probably cost at
least $20,000 (and likely a good bit more) to duplicate the
structure today.

If Successful, Be Prepared to Share the Wisdom

Naturally, when the news that someone was successfully
using solar energy in the fogbelt began to filter out to a
wider world, Matthew was flooded with requests for
information. In order to keep up with the deluge of mail
and phone calls, he drew up some rough plans of his solar
home. Matthew has updated the material from time to time,
but he warns that some of the information could probably
profit from more "modernization."

"After all," he says,
"we've learned a lot about using solar power in the last 15
years."

In order to put some of that more recent knowledge to use, Matthew is now in the process of putting the finishing
touches on a second solar house, a scant mile east of his
present home.

"Since the new location is a bit farther from
the ocean, it gets colder in the winter and hotter in the
summer. Also, the site is partially shaded on winter
afternoons, and that forced me to face my collectors
18 degrees toward the east. I've overbuilt the solar
heating system by 25 percent to 30 percent, using three rows of roof
collectors. However, they're so compact that, if you were
to just drive by, you'd never know the house is solar
heated.

"My new collectors are built to tolerate temperatures of
around 350 degrees Fahrenheit. They're backed with metal instead of
plywood and I used preformed aluminum flashing that
enabled me to snap the pipes in place, rather than tying
them on with wire. In addition, I installed corrugated
fiberglass, which costs only half as much as glass. These
panels are glued in place with transparent silicone and are
holding up well against our winter rain, hail, and 100-MPH
winds. The roof also has a tremendous 60-foot-wide
reflecting area, which — again — is simply a
single layer of aluminum foil over bare plywood. I figure
that the barrel and a half of roofing cement cost about
$90, and the aluminum foil was about $60, which amounts
to a pretty inexpensive way to double a collector s
efficiency."

The storage tank for the new house is also larger (9,200
gallons) and is insulated with 3-1/2 inches of fiberglass all
around, so the stored heat isn't carried through to the
ground.

The nearly completed three-bedroom, two-bath, dwelling cost
Matthew $26,000 ($6,000 for the land and $20,000 for
materials), $3,850 of which went into the solar system.
But, again, he did all the labor himself, even bulldozing
his own road in and preparing the construction site.

MOTHER EARTH NEWS asked Henry whether, after all his years of
experience, he'd encountered any problems while
constructing the second building.

"With the single rooftop collector on my first house," he
replied, "all the water drains back into the storage tank
whenever the pump stops. But the new home's three
collectors don't all drain instantly or at the same time,
and this fact occasionally caused air to get into the line.
Then, if the pump happened to start up just as an air
pocket hit it, it would lose power. I solved the problem by
putting in about 3 feet of 6-inch pipe, to allow the bubbles to
rise out of the system."

Matthew also found that his new storage tank, which was built
in four parts, was subjected to great changes in pressure
when the pump started up and eventually one whole
section caved in: "I had to weld a lot of heavy steel over
the top to reinforce it.

"I can't really say that I had any other problems," he grinned. "I did make a lot of changes in the
piping system as I went along because I just seemed to
keep getting new ideas."

Well, that doesn't surprise us a bit. After all, how can a
person be a pioneer without new ideas?

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